Find u ∙ v.
1. u = (7, 1)
v = (−3, 2)
2. u = (6, 10)
v = (−2, 3)
3. u = (−6, 2)
v = (1, 3)
4. u = −2, 5
 v = (−1, −8)
5. u = (4i − 2j)
v = (i - j)
6. u = (i − 2j)
v = (−2i - j)